This part of the IEC 60846 series applies to portable or transportable dose equivalent (rate) meters and/or monitors for the measurement of ambient and/or directional dose equivalent (rate) from external beta, X and gamma radiation during emergency situations. It applies directly to dose equivalent (rate) meters intended for the determination of the dose equivalent or dose equivalent rate from external beta and/or X and gamma radiation of energies up to 10 MeV during emergency situations. The object of this part of the IEC 60846 series is to specify the design requirements and the performance characteristics of dose equivalent (rate) meters intended for the determination of ambient and/or directional dose equivalent (rate) as defined in ICRU Report 47 under emergency conditions. With the exception of modified or new clauses listed below, all clauses in IEC 60846:2002 are applicable for instruments used for emergency purposes. This part of the IEC 60846 series does not specify which instruments are required nor does it consider the numbers or specific locations of such instruments. This part of the IEC 60846 series does not identify instrumentation for specific types of accidents. It is essential that the rated ranges of the instruments and the radiological and non-radiological conditions for which the instruments are designed adequately cover the accident and post-accident conditions as determined by accident analysis and/or specified by appropriate regulatory authorities or qualified individuals. It is expected that accidents will involve both dose equivalent (rate) and environmental extremes (e.g. temperature and humidity). Specifications for instruments for measuring dose equivalent rates less than the minimum detectable dose rate level specified in this part of the IEC 60846 series are contained in IEC 60846:2002. Where such instruments are also to be used for emergency measurements, they shall also meet the requirements of this part of the IEC 60846 series. Although this part of the IEC 60846 series specifies the requirements for instruments primarily for emergency use, such instruments may also be used for on-site measurements at other times. If the instrument has a remote detector and if an additional detector is provided in the measuring assembly to measure dose equivalent rate at the location of the operator, the requirements shall apply to both of the detectors.